Return result from `gettext::Messages::from_file`

Instead of panicking on error.

4 files changed, 41 insertions, 10 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 57d8b725ae..781f984822 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -257,6 +257,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "convert_case"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
+
+[[package]]
 name = "core-foundation"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -386,6 +392,18 @@ dependencies = [
 ]
 
 [[package]]
+name = "derive_more"
+version = "0.99.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f82b1b72f1263f214c0f823371768776c4f5841b942c9883aa8e5ec584fd0ba6"
+dependencies = [
+ "convert_case",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "digest"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -3038,6 +3056,7 @@ dependencies = [
 name = "translations-converter"
 version = "0.1.0"
 dependencies = [
+ "derive_more",
  "htmlize",
  "lazy_static",
  "regex",
diff --git a/android/translations-converter/Cargo.toml b/android/translations-converter/Cargo.toml
index a5f01aa386..50b410de29 100644
--- a/android/translations-converter/Cargo.toml
+++ b/android/translations-converter/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+derive_more = "0.99"
 htmlize = "0.5"
 lazy_static = "1"
 regex = "1"
diff --git a/android/translations-converter/src/gettext/messages.rs b/android/translations-converter/src/gettext/messages.rs
index 5effebf1b5..2b2777f78c 100644
--- a/android/translations-converter/src/gettext/messages.rs
+++ b/android/translations-converter/src/gettext/messages.rs
@@ -1,4 +1,5 @@
 use super::{msg_string::MsgString, parse_line, plural_form::PluralForm};
+use derive_more::{Display, Error, From};
 use std::{
     collections::BTreeMap,
     fs::File,
@@ -57,7 +58,7 @@ impl Messages {
     /// msgstr[0] "Unu tradukita mesaĝo"
     /// msgstr[1] "%d tradukitaj mesaĝoj"
     /// ```
-    pub fn from_file(file_path: impl AsRef<Path>) -> Self {
+    pub fn from_file(file_path: impl AsRef<Path>) -> Result<Self, Error> {
         let mut parsing_header = false;
         let mut entries = Vec::new();
         let mut current_id = None;
@@ -68,12 +69,11 @@ impl Messages {
         let file = BufReader::new(File::open(file_path).expect("Failed to open gettext file"));
         // Ensure there's an empty line at the end so that the "else" part of the string matching
         // code will run for the last message in the file.
-        let lines = file
-            .lines()
-            .map(|line_result| line_result.expect("Failed to read from gettext file"))
-            .chain(Some(String::new()));
+        let lines = file.lines().chain(Some(Ok(String::new())));
+
+        for line_result in lines {
+            let line = line_result?;
 
-        for line in lines {
             match_str! { (line.trim())
                 ["msgid \"", msg_id, "\""] => {
                     current_id = Some(MsgString::from_escaped(msg_id));
@@ -142,10 +142,10 @@ impl Messages {
             }
         }
 
-        Self {
+        Ok(Messages {
             entries,
             plural_form,
-        }
+        })
     }
 }
 
@@ -163,3 +163,10 @@ impl From<MsgString> for MsgValue {
         MsgValue::Invariant(string)
     }
 }
+
+#[derive(Debug, Display, Error, From)]
+pub enum Error {
+    /// IO error while reading input file.
+    #[display(fmt = "Failed to read from the input file")]
+    Io(std::io::Error),
+}
diff --git a/android/translations-converter/src/main.rs b/android/translations-converter/src/main.rs
index c985061c32..8444470cd3 100644
--- a/android/translations-converter/src/main.rs
+++ b/android/translations-converter/src/main.rs
@@ -98,19 +98,23 @@ fn main() {
             fs::create_dir(&destination_dir).expect("Failed to create Android locale directory");
         }
 
+        let translations = gettext::Messages::from_file(&locale_file)
+            .expect("Failed to load translations for a locale");
+
         generate_translations(
             locale,
             known_urls.clone(),
             known_strings.clone(),
             known_plurals.clone(),
-            gettext::Messages::from_file(&locale_file),
+            translations,
             destination_dir.join("strings.xml"),
             destination_dir.join("plurals.xml"),
         );
     }
 
     let template_path = locale_dir.join("messages.pot");
-    let template = gettext::Messages::from_file(&template_path);
+    let template = gettext::Messages::from_file(&template_path)
+        .expect("Failed to load messages template file");
 
     let mut missing_translations = known_strings;
     let mut missing_plurals: HashMap<_, _> = known_plurals;